Field of the Invention
The present invention relates to an in-cell touch liquid crystal display (LCD) device having a common electrode top structure and a method of manufacturing the same.
Discussion of the Related Art
Replacing a mouse, a keypad or a keyboard which has been conventionally applied to flat panel display devices, a touch screen that enables a user to directly input information with a finger or a pen is being widely applied to the flat panel display devices. Especially, since any users can easily manipulate the touch screen, the application of the touch screen is being expanded.
A touch screen is widely applied to monitors of navigations, industrial terminals, notebook computers, financial automation equipment, and game machines, portable terminals such as portable phones, MP3 players, PDAs, PMPs, PSPs, portable game machines, DMB receivers, and tablet personal computers (PCs), and home appliances such as refrigerators, microwave ovens, and washing machines.
The touch screen may be classified as following types based on a structure where the touch screen is coupled to a liquid crystal panel. The types of the touch screen include: an in-cell touch type in which the touch screen is built in a cell of a liquid crystal, an on-cell touch type in which the touch screen is disposed on a cell of a liquid crystal panel, an add-on type in which the touch screen is coupled to an outer portion of a liquid crystal display panel, and a hybrid type.
Hereinafter, a device where a touch screen (a touch panel) is combined with a liquid crystal panel is simply referred to as a touch LCD device.
FIG. 1 is a diagram illustrating a related art touch LCD device to which a touch screen is applied. FIG. 1(a) illustrates an add-on type touch LCD device. FIG. 1(b) illustrates a modified add-on type touch LCD device. FIG. 1(c) illustrates a hybrid type touch LCD device.
In the add-on type touch LCD device of FIG. 1(a) and the modified add-on type touch LCD device of FIG. 1(b), a touch screen is disposed on a liquid crystal panel that includes a thin film transistor (TFT) array substrate 1 and a color filter array substrate 2. A touch driving electrode (a TX electrode) and a touch receiving electrode (an RX electrode) are arranged in the touch screen. In this case, the touch driving electrode (the TX electrode) and the touch receiving electrode (the RX electrode) may be disposed on the same layer or different layers.
In the hybrid type touch LCD device of FIG. 1(c), a touch driving electrode (TX) is disposed on a TFT array substrate 1, and a touch receiving electrode (RX) is disposed on a color filter array substrate 2.
In a touch LCD device based on an add-on type, a modified add-on type, or a hybrid type, since a liquid crystal panel and a touch screen should be separately manufactured, a process of manufacturing the touch LCD device is complicated, and the cost increases. Also, defects can be generated in a process of bonding the liquid crystal panel to the touch screen.
Therefore, an in-cell touch LCD device where a touch electrode (a touch sensor) is embedded into a cell of a liquid crystal panel has been developed to reduce a thickness of a touch LCD device and the manufacturing cost. The in-cell touch LCD device uses a common electrode, which is disposed on a TFT array substrate, as a touch sensor.
FIG. 2 is a diagram illustrating a related art in-cell touch LCD device based on a mutual capacitance type.
Referring to FIG. 2, in the related art in-cell touch LCD device based on the mutual capacitance type, common electrodes which are arranged on a TFT array substrate of a liquid crystal panel 10 are used as a touch driving electrode (TX) and a touch receiving electrode (RX).
In the related art of the in-cell touch LCD device based on the mutual capacitance type, a touch driving line 12 connected to the touch driving electrode (TX) is disposed in each of a left bezel area and a right bezel area of the liquid crystal panel 10.
For this reason, a bezel width of the in-cell touch LCD device increases.